bonzer: To zlaywal, timppu, randalator, groot, hereforthebeer (do you know how hard it is to type your name without spaces?)
On speedtest.net...Ping 18ms, D/L 5.15Mbps, U/L 0.26Mpbs
Yeah like someone guessed, you have a 5 Mbps line then. I guess it is ok'ish, albeit in many places 10Mbps is considered as the basic level broadband connection nowadays (and heavy users have 100Mbps or even 1000Mbps (=1Gbps), and your connection might not be fast enough for HD Netflix).
i have a 10Mbps cable modem connection myself, and I am pretty happy with it, still. It is included in the basic housing costs of my apartment. I could upgrade it to 100Mbps for something like 15€/month, but I am too cheapskate to do that right now.
Your upload speed is quite low though, but then that shouldn't affect your download speeds from GOG or elsewhere. It would only matter if you needed to send some big files to elsewhere (e.g. upload a big video from your computer to Youtube).
EDIT: And yeah the answer to your original question, your GOG download speeds seem ok considering your internet connection.
Themken: 18ms ping time is very, very good; many an online gamer is green of envy. It may be normal for fibre but over copper not.
Oh, is it? When I ran the speedtest yesterday on my basic 10Mbps cable modem, I got 12ms ping. I think I am getting similar also when using my 4G LTE phone for internet (connected to the PC with an USB cable). Note that the ping times I get on online games like Team Fortress 2 may be considerably higher (like 30-50ms), depending where exactly the server is. Speedtest.net uses some nearby test server for the tests where low ping times are expected.
I don't know what kind of wiring the cable modem has, I presume it is copper? This is not a new house, built in the 80s.